This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 17 |
| 5 | 40 |
| 6 | 94 |
| 7 | 222 |
| 8 | 526 |
| 9 | 1252 |
| 10 | 2994 |
| 11 | 7191 |
| 12 | 17343 |
| 13 | 41989 |
| 14 | 102023 |
| 15 | 248712 |
| 16 | 608168 |
| 17 | 1491349 |
| 18 | 3666685 |
| 19 | 9037003 |
| 20 | 22323243 |
| 21 | 55259206 |
| 22 | 137058248 |
| 23 | 340567477 |
| 24 | 847711177 |
| 25 | 2113455657 |
| 26 | 5277115687 |
| 27 | 13195311961 |
| 28 | 33038994039 |
| 29 | 82829585094 |
| 30 | 207905352180 |